וַיֹּ֨אמֶר עֵלִ֣י לִשְׁמוּאֵל֮ לֵ֣ךְ שְׁכָב֒ וְהָיָה֙ אִם־יִקְרָ֣א אֵלֶ֔יךָ וְאָֽמַרְתָּ֙ דַּבֵּ֣ר יְהוָ֔ה כִּ֥י שֹׁמֵ֖עַ עַבְדֶּ֑ךָ וַיֵּ֣לֶךְ שְׁמוּאֵ֔ל וַיִּשְׁכַּ֖ב בִּמְקוֹמֽוֹ׃
Therefore Eli said unto Samuel: ‘Go, lie down; and it shall be, if thou be called, that thou shalt say: Speak, LORD; for Thy servant heareth.’ So Samuel went and lay down in his place.
Read halakhic rulings (Jewish law) on I Samuel 3:9: and classical halakhic sources.